1. Field of the Invention
This invention relates to an apparatus for permitting regulatable variation of the friction grip between the wheels of a car and a supporting surface. This invention is directed toward over-the-road vehicles and more particularly to driver training for various types of road conditions simulated by reducing the coefficient of rolling friction between the wheels of a car and a roadbed.
Heretofore such training usually has been achieved by providing special roadbeds in which a friction reducing material was spread over the surface of the roadbed before placing a car with a driver to be trained thereon.
The principal disadvantage of this method resides in the expense of preparing such a road surface and thereafter removing the friction reducing material. Further, it requires a preferably level surface such as a parking lot and in areas of high land use such areas are relatively expensive particularly when such road surfaces are used only for driver training.
2. Description of the Prior Art
U.S. Pat. No. 4,700,798 discloses a driver training apparatus for simulating skidding conditions of automobiles. This patent discloses a frame which underlies the frame of a vehicle and is connected with its suspension system and further provides caster wheels adjacent but spaced outwardly from the respective automobile wheel with these caster wheels being elevated or lowered relative to the automobile supporting frame for reducing the frictional contact between the car wheels and the surface of a roadbed.
This invention is distinctive over this patent by providing forward and rearward articulating axles which support caster wheels in outrigger fashion relative to the four wheels of a car, raise and lower the caster wheels relative to the car and act to tilt the pivoting axis of the caster wheels in a forward or rearward direction with respect to the vertical which achieves a forward steering stabilizing effect on the car in any situation whether turning in forward direction or during a simulated skid. Further, these articulated axles act as breaking means if necessary.